The national pork producers demand the application of tariffs to the imports of originating meat pig of the EUA arguing a serious damage to the industry whereas, on the other hand, the governmental authorities reject this option, reason why the evaluation of the impact of its implantation like an alternative is justified that it causes to improve the competitiveness of the national pork industry. In order to analyze this effect a model of partial balance was used Armington type, using the data of 2006 of the international trade of pig meat. The results indicate that if a tariff of 20 % to the originating meat of the United States of America and Canada in the 2008 had been applied the demand by Mexico of its meat would have lowered 9.6 and 27.5 %, whereas the demand of national meat would have increased 6.4%. In addition, the production would have risen in 4.5 % and the internal price raised 12.5 %. By another part, if the tariff had been only applied to the United States, the demand in Mexico of originating meat of this country would have lowered 23.4 %, the one of Canada and the national would have increased 5.4 and 3.4 % respectively, whereas the 2.4 % production would have been increased and price 6.6 %. It is expected that the 5.0% tariff imposed by Mexico in 2010 to purchases of pork from the United States of America generate changes few significant to the domestic market. Reason why, if tariffs are applied to the meat of EUA pig and Canada when its price is smaller to the national production costs the increase in the internal price would help the national pork industry to be competitive.

Los porcicultores nacionales demandan la aplicación de aranceles a las importaciones de carne cerdo provenientes de los EUA argumentando un daño grave a la industria en tanto que las autoridades gubernamentales desechan esta opción, por lo que se justifica la evaluación del impacto de su implantación como una alternativa que propicie mejorar la competitividad de la porcicultura nacional. Para analizar este efecto se utilizó un modelo de equilibrio parcial tipo Armington, utilizando datos de 2006 del comercio internacional de carne de cerdo. Los resultados indican que si se hubiera aplicado un arancel del 20.0 % a la carne proveniente de Estados Unidos de América y Canadá en 2008 la demanda por México de su carne habría bajado 9.6 y 27.5 %, mientras que la demanda de carne nacional habría aumentado 6.4 %. Además, la producción se habría elevado en 4.5 % y el precio interno subido 12.5 %. Por otra parte, si el arancel solamente se hubiera aplicado a los Estados Unidos, la demanda en México de carne proveniente de este país habría bajado 23.4 %, la de Canadá y la nacional habrían aumentado 5.4 y 3.4 %, mientras que la producción se habría incrementado 2.4 % y el precio 6.6 %. Se espera que el arancel de 5.0 % impuesto por México en 2010 a las compras de carne de cerdo de Estados Unidos de América genere cambios poco significativos al mercado nacional. Por lo que, si se aplican aranceles a la carne de cerdo de EUA y Canadá cuando su precio es menor a los costos de producción nacionales, el incremento en el precio interno ayudaría a la porcicultura nacional a ser competitiva.

A by-product from olive oil production, olive stone, was investigated for the removal of Cd (II), Cr (III) and Pb (II) from aqueous solutions. The kinetics of biosorption are studied, analyzing the effect of the initial concentration of metal and temperature. Pseudo-first-order, pseudo-second-order, Elovich and intraparticle diffusion models have been used to represent the kinetics of the process and obtain the main kinetic parameters. The results show that the pseudo-second order model is the one that best describes the biosorption of the three metal ions for all the range of experimental conditions investigated. For the three metal ions, the maximum biosoption capacity and the initial biosorption rate increase when the initial metal concentration rises. However, the kinetic constant decreases when the initial metal concentration increases. The temperature effect on biosorption capacity for Cd (II) and Cr (III) is less significant; however, for Pb (II) the effect of temperature is more important, especially when temperature rises from 25 to 40ºC. The biosorption capacity at mmol/g of olive stone changes in the following order: Cr>Cd>Pb. Thus, for an initial concentration of 220 mg/ℓ, a maximum sorption capacity of 0.079 mmol/g for Cr (III), 0.065 mmol/g for Cd (II) and 0.028 mmol/g for Pb (II) has been obtained.